Telephone plug



May 8, 1928. 1,669,042

G. G. CROMARTIE ET AL TELEPHONE PLUG Filed Nov. 39, 1924 ll- IIIIIIII ATTORNEY Patented May 8, 1928.

UNITED STATES PATENT OFFICE.

GEORGE G. CROHARTIE, OF EAST ORANGE, AND EINAR W.

NIELSEN, OF NEWARK,

NEW JERSEY, ASSIGNORS, BY MESNE ASSIGNMENTS, TO SEABOARD ENGINEERING CORPORATION, OF NEWARK, NEW JERSEY, A CORPORATION OF NEW JERSEY.

TELEPHONE PLUG.

Application filed November 29, 1924-. Serial No. 752,875.

This invention relates to electric plugs and particularly toplugs adapted and intended to be used in telephone or other electrical circuits in which currents of low potential are transmitted. I v

The general object of the invention is to provide a new and improved telephone plug which is cheap to manufacture, simple in construction, eflicient in use and adapted for connection conveniently to conductors provided with so called telephone cord tips of a well-known kind.

One of the advantages of the present invention resides in the fact that telephone plugs constructed in accordance with it may be readily attached to conductors provided with cord tips without taking the plug apart or removing or adjusting any parts thereof, and without the use of any tools whatever. Owing to certain features of internal construction which will be hereinafter described, cord tips on the ends of telephone or other conductors may be secured to the plug in electrical connection with the contact members thereof merely by pushing the tips into cavities in the plug handle in which they are automatically held in a manner which preventstheir accidental withdrawal,

while still permitting them to be readily removed when desire The invention will be understood from the following description, taken in connection with the accompanying drawing, in which Figure 1 is a side elevationof a telephone plug embodying the invention, with a portion of the handle removed, and with the remaining portion of the handle shown in section on line 1-1 of Figure 2; Figure 2 is a plan view of the plug, with one of the handle portions removed. and with certain parts shown in section; Figure 3 is a plan view of the plug, with a portion of'the handle broken away to show the manner in which cord tips are held within the plug; and Figure 4 is a plan view similar to Figure 3, showing one of the cord tips fully and the other partially inserted in the plug,

Referring to the drawing, the plug therein illustrated is shown as having a tip contact 5 and a sleeve cont-act 6 insulated therefrom by the washer 7, these contacts being sup orted by and projecting fronra handle ma e of bakelite or other suitable material will be hereinafter described in detail. As shown, the tip contact 5 is secured to or integral with a rod 10 which extends through the sleeve 6, and at its end is provided with a nut 12. Clamped between the nut 12 and the end of the shell 6 are the perforated ends of contact springs 13 and '14, the form of which will be apparent from the drawing. As shown in Figures 1 and 2, the contact spring 14 1s in engagementwith the end of the sleeve 6 and thus is in electrical contact w1th 1t, a washer 16 of fibre or other in- ,sulatlng material being interposed between the perforated end of the spring14 and the rod 10. The spring 13 is in electrical contact with the rod 10, owing to the fact that the nut 12 is in engagement with said spring, a washer 18 of fibre or other suitable material being interposed between the springs 13 and 14 so as to insulate them from one another. The contact spring 13 is thus in electrical contact with the sleeve 6. Owing to the fact that the tip and sleeve contacts 5 and 6. and the contact springs 13 and 14 are mechanically, as well as electrically associated, these parts may be assembled separately from the handle and then inserted in the latter. In order to bring the free ends of the springs 13 and 14 into alignment with each other, the spring 13, which is the same length as the spring 14, is provided with a bent portion 40 intermediate its ends, as shown in Figure 2, thereby shortening its effective length and compensating for its spaced relation with reference to the spring 14.

The complementary handle parts 8 and are provided with cavities 20 and 21 of the Shape shown, which form recesses within the handle when the parts of the latter are assembled. It will be noted that these recesses are adapted to receive the contact springs 13 and 14 which, throughout a portion of their length, lie alongside the outer walls of said recesses; and that the rounded ends of the springs 13 and 14 are free to move in an enlarged portion of the cavities 20 and 21. As clearly shown in the drawing, the cavities 20 and 21 in the handle portions are separated by a middle wall 23 which partially conforms on each side, as shown at 24 and 25, to the form of a telephone cord tip. It will also be apparent that the entrances to the recess in the plug handle are provided on the side thereof adjacent the middle wall with cord-tip-engaging lugs or shoulders 27 and 28, the function of which is hereinafter explained. v

Referring now to the Figures 3 and 4, it will be evident that when telephone cord tips of the usual form are inserted through the openings in the end of the plug handle, they will engage the contact springs 13 and 14 and will flex the latter into the positions shown in Figure 3. During the operation of inserting a cord tip in the plug handle, the .contact springs 13 and 14 will at first engage the reduced end 30 of the tip, as shown at the bottom of Figure 4; and will finally engage the larger portion 31 .of the cord tip as shown in Figure 3 and at the top of Figure 4. After the cord tips have been inserted in the handle as far as shown in Figure 3, portions 30 and 31 of the cord tips will lie in engagement with the middle wall 23 between the recesses in the plug, and will be yieldingly held in that position by the contact springs 13 and 14. While in this position, the rear ends of the enlarged portions 31 of the cord tips will engage the shoulders '27 and 28 which will efi'ectively prevent withdrawal of the tips from the plug if both of the conductors 33 and 34 are grasped and pulled, as often happens when the plug is in use. If, however, the user I desires to disconnect the cord tips from the plug, this may be easily effected by separately grasping each conductor 33 and 34 .and moving its tip laterally within the plug handle against the pressure exerted by the contact spring 13 or 14 until the rear end of the cord tip is out of engagement with the shoulder 27 or 28, whereupon the tip can be withdrawn from the plug handle. Withdrawal of the cord tips, after the rear ends thereof have been disengaged from the shoulders 27 and 28, is facilitated by the pressure exerted by the springs 13 or 14 on the cord tip tending to eject it as the spring slides over the shoulder between the enlarged the tip.

Owing to the fact that the cord tips may be inserted in and withdrawn from the plug handle without taking the plug apart or removing or adjusting any parts thereof, the handle ortions 8 and 9 are preferably permanent y secured together by rivets 36 or in any other suitable manner. The chance of improper manipulation of the .parts of the plug by the user, is thus reduced to a mlmmum.

While the form of the invention herein shown and described is the preferred embodiment thereof, it is to be understood that various modifications may be made without depialrtmg from the spirit of the invention as de ed in the claims hereto appended.

What we claim is:

1. A telephone plug comprising a handle portion having recesses therein separated by a middle wall partially conforming on each side to the form of a telephone cord tip, a shoulder formed in said handle portion at the entrance to each of said recesses on the side thereof adjacent said middle wall, a contact spring arranged within each of said recesses and adapted to engage a cord tip therein and yieldingly-liold it against said middle wall with the rear end of said tip in engagement with the inside of the shoulder at the entrance to the recess, and contact members electrically connected to said springs and projecting from said handle portion.

phone cerd tip, a middle wall arranged in-.

termediate said recesses, cord-tip-engaging lugs located at opposite sides of said wall adjacent said wall and the entrances to said recesses and adapted to cooperate with the rear ends of the cord tips, and springs arranged within said recesses and adapted to engage cord tips and urge the same towards said wall and yieldably retain them positioned in front of said lugs.

3. A telephone plug comprising the tip contact, a sleeve contact. said contacts being respectively adapted for connection with telephone cord tips, a handle portion in two partshaving complementary cavities therein forming recesses, each of said recesses being adapted to receive a telephone cord tip, a'middle wall arranged intermediate said recesses, cord-tip-engaging lugs located at opposite sides of. said wall adjacent said wall and the entrances to said recesses and adapted to cooperate with the rear-ends of v and yieldably retain them positioned in portion 31 and the smaller portion 30 of front of said lugs.

4. A connector comprising a handle portion in two parts having complementary cavities therein forming recesses, each of said recesses being adapted to receive a telephone cord tip, a middle wall arranged intermediate said recesses cord-tip-engaging lugs located at opposite sides of said wall adjacent said wall and the entrances to said I recesses and adapted to-cooperate with the rear ends of the cord tips and springs, ar-

ranged within said recesses and adapted to engage cord tips and urge the same toward said wall and yieldably retain them positioned in front of said lugs.

5. An electric connector including a body having openings in one end for the insertion of cord tips into the body and also'havingrecesses in communication with said openlugs for the reception of said tips, adjacent Walls of said recesses being formed by a longitudinally extending central portion having indentations on opposite edges providing a locking projection at the outer end of each recess adjacent the associated opening and behind which is adapted to engage a portion of one of said tips, and spring connectors carried by said body and each having a portion projecting into one of said recesses and acting to move the tip therein into locking engagement with the adjacent projection when said tip is inserted into its opening.

6. An electric connector including a body having openings in one end for the insertion of cord tips into the body and also having recesses in communication with said openings for the reception of said tips, adjacent walls of said recesses being formed by a longitudinally extending central portion having indentations on'opposite edges providing a locking projection at the outer end of each recess adjacent the associated opening and behind which is adapted to engage a portion of one of said tips, and spring connectors carried by said body and each having a portion projecting into one of said recesses and acting to move the tip therein into locking engagement with the adjacent projection when said tip is inserted into its opening, said tip being releasable from its recess only by a. lateral movement of the tip relative to said central portion and against the tension of said spring connector to disengage the tip from its locking projection.

7. A connector comprising a body portion having recesses, each of said recesses being adapted to receive a telephone cord tip, a middle wall arranged intermediate said recesses, cord tip engaging lugs located on opposite sides of and adjacent said wall and the entrance to said recesses, adapted to cooperate with the rear ends of the cord tips. and springs adapted to urge the rear ends of the cord tips towards said wall and yielditbly retain them positioned in front of said ugs.

8.- An electric connector including a body having openings in one endthereof for the insertion of cord tips and also having recesses in communication with said openings for the reception of said tips, adjacent walls of said recesses being formed by a longitudinally extending central portion having indentations on opposite edges providing a locking projection at the outer end of each recess adjacent the associated opening and behind which is adapted to engage a portion of one of said tips, with the free extremity of said tip contacting said central portion inwardly of the adjacent indentation, and spring connectors carried by'said body and each having a portion projecting into one of said recesses and acting to move the tip ,therein into locking engagement with the adjacent projection when said tip is inserted into its opening, said tip being releasable from its recess only by a lateral movement of its outer end against the tension of said spring connector, the free inner end of said tip being held in engagement with said central portion by said connector during said lateral movement.

9. An electric connector including a body having an opening at one end for the insertion of a cord tip and also having a recess for receiving said tip, a locking projection formed at said opening as a part of one wall of said recess, and a spring connector having a portion disposed in said recess in alignment with said opening and acting to move said tip laterally into locking engagement with said projection as the tip is inserted through said opening and into said recess.

GEORGE G. CROMARTIE. EINAR W. NIELSEN. 

